Traction-pulley.



P. G. GARDNER.

TRACTION PULLEY. APPLICATION FILED MAR 22. 1912.

Patented Apr. 23, 1918.

$51 attorney;

JPERRY e. GARDNER, or RUTHERFORD, NEW JERSEY,.ASSIGNOR TO ROUND ERooKonn LESS BEARING coMrANY, or RoUNnBRooK, NEW JERSEY, A CORPORATION on NEW JERSEY.

incense.

Specification of Letters Patent.

'rRAcrIoN-rULLEY.

Application filed March 22, 1917. Serial No. 156,732.

tain new and useful Improvements in Traction-Pulleys, of which the following is a specification.

The invention relates to pulleys and is designed to maintain a belt driven thereon obviating side slip and thus holding the belt in a central position.

The object of the invention is to provide a pulley with cups or depressions formed either in the pulley or in the covering there- ,for in a manner to prevent side slip of the belt to give a maximum of non-slip or traction efiect between the pulley and its belt and prevent slippage.

Referring to the drawings:

Figure l is a perspective view of a pulley with a belt sectlon applied thereto.

Fig. 2 is a fragmentary view in section and perspective on enlarged scale.

Fig. 3 is a view illustrating the relative position of belt and pulley-face.

Fig. 4 is a fragmentary view in section through the pulley and appurtenant parts.

It is a well known condltlon in engineering that belts will ride off the surfaces of pulleys, and ordinarily pulleys are coned up or crowned at their medial line to hold the belts at central running position.

It is also a well lmown fact that belts will slip under unusual driving torques.

It is the principal object of the present invention to prevent slippage and to hold the belt to proper center. To accomplish this, either the pulley itself or an intermediate member encompassing the pulley and lying between the pulley and the belt is provided with traction cups of a unique form. These act upon the belt, holding it against slip in its running and will give a traction between the belt and the pulley which will prevent slippage in direct drive of the belt, and will also prevent relative sidewise movement of the belt and pulley. The advanced points of the cups, in running, tend to hold the belt in proper running position upon the pulley. If there is any tendency of the belt to run ofi as it breaks away from the forward end of the cups, the points at the rear end of the cups have a tendency to correct the movement. This action is probably dueto the fact that the advanced points of the openings of the cups are in the same line with the advanced points at the rear of the cups and any slight lateral movement at the forward end, as it breaks away from the belt, is immediately corrected by the holding of the belt on the advanced points at the rear of the openings. At any rate, formation of the cups, as indicated in practice shows a marked tendency to prevent oil running of the belt.

Referring to the drawings, the numeral 1, indicates a pulley which may be of any desired type or form and, as illustrated, has an exterior member 2.

This illustration indicates the possibility of applying the device to any pulley now commonly in use, and it is obvious that, in lieu of the eXterior member 2, the traction pockets might be formed directly in the face of the pulley. In fact, for purposes of illustration and description, the pulley 1, with its exterior peripheral covering 2, may be considered as a homogeneous structure.

The peripheral face of the pulley or its COVBI'lIlg' is provided with traction cups 3. These are of a peculiar formation in that there is a leading point 4, having diagonally projecting walls 5, 6, and parallel walls 7, terminating at the end of the cup or opening in diagonal walls 8, which are substantially in parallelism with the walls 5, 6.

As the pulley drives, the belt, there is always a tendency for the air pressures induced in the traction cups 3., to equalize and cause a straight run or movement of the belt between the point 9, formed by the walls 8, and the point 4, formed by the walls 5, and 6.

There is ample space 10, on the face of the pulley between the various traction cups to give strength and stability to the pulley and to permit a break of suction between the various lines of traction cups.

This construction provides against overtraction between the pulley and its belt and releases the suction at the point of drive on the periphery of the pulley where the belt leaves the pulley.

the line of contact where the belt should leave the pulley.

The traction cups 3, roll into engagement with the belt point on expelling air from the rear end of the cups, creating a holding suction through the expulsion and breaking the suction as they come to the opposite point of the meeting walls. This prevents undue holding and yet gives complete adhesion between the belt and pulley.

Of course, the exact arrangements of the cups as illustrated may be varied to any desired degree and any number of cups may be employed so long as the walls of the cups are parallel to the running direction of the pulley upon two sides and are obliquely arranged to said sides and form central meeting points at opposite ends of the cups.

. A plurality of peripheral lines of cups are herein 'shownwhich are arranged in parallel axial lines, but it is quite possible that a single line might be employed at the central line of the pulley.

To give the greatest traction effect possible, the cups may be formed in an exterior flexible member applicable to the face of a pulley. In this instance, the pulley-face will form the bottom of the suction cups. In such an application of the device a shield or covering might be made any dimension to slip over the exterior of any ordinary pulley and be suitably secured thereto.

In the event of ordinary application, the suction cups may be formed directly in the face of the pulley.

What I claim as my invention and desire to secure by Letters Patent is:

1. A pulley having traction cups providing direct adherence for a belt and gradually relieving said belt when moving tangentially with reference to the periphery of the pulley.

2. A pulley having traction cups arranged about its periphery and in series of rows to provide direct adherence for the belt, said cups having side walls and forwardly extending end walls, said end walls providing means for releasing said belt when moving tangentially with reference to the periphery of the pulley.

3. A pulley having traction cups, said cups having their side walls parallel and extending about the pulley, the forward end of said cups having walls projecting in advance of the side walls, and the rear ends of the cups projecting into the area between the side walls and with the meeting ends of the oblique walls at the front and rear of the cups arranged in the same line on the pulley.

4:. A pulley having traction cups, said cups having their side walls parallel. and in the circumferential lines of the pulley the forward end of said cups having angularly disposed walls projecting in advance of the side Walls, and the rear ends of the cups projecting into the area between the side walls and with the meeting ends of the oblique walls at the front and rear of the cups arranged in the same circumferential lines of the pulley, said cups arranged in series transversely of and peripherally of the pulley.

PERRY G. GARDNER.

Witnesses;

Gno. S. SMALLEY, E. LOWANDE. 

